In California, if a spouse has been absent or cannot be located, the court in which the divorce petition has been filed can issue a separate order to authorize service by publication, upon the affidavit of the spouse petitioning for the divorce (California Code of Civil Procedure 415.50). After such publication and there is still no word from the other spouse, then he/she will be in default.
For such order could be issued by the court, the spouse filing the petition should submit an affidavit to prove that he/she has exercised “due diligence” in locating the other spouse, meaning all the possible reasonable means of knowing the whereabouts of the other spouse has been exhausted [California Family Code 2336]. This publication should be in a well-known newspaper published within the State or in another named newspaper outside the State where the petition was filed if there is reason to believe that the absent spouse might be living outside that state. Service by publication is only a “last resort” when all other means of serving (personally or through mail) would be impossible.
In such cases, a default or uncontested dissolution judgment may be given. But it may be a very tricky process if one is not familiar with the laws of the State regarding such matters, that’s why the best course is to speak and work with an experienced divorce lawyer who could explain the whole process clearly and accurately.